The stiffness estimation of steel semi-rigid beam–column moment connections in a fire

This study investigates the estimation of the stiffness of steel semi-rigid beam–column moment connections in a fire. The general purpose finite element software ANSYS is adopted. The parameters, such as material properties and geometric conditions, are fully studied to investigate their effect on stiffness. The formula for the stiffness of steel semi-rigid beam–column moment connections, which are made with the H-beam and H-column, for the case of constant temperature with increasing vertical beam load is proposed and verified by the results of ANSYS analysis. The stiffness of steel beam–column connections for the case of increasing temperature with constant load estimated by the proposed formula is found to be conservative.